ftrace

Starts tracing function-spec, which can be a
function name (such as a symbol naming a function) or a function
object (such as returned by function applied to a symbol naming a
function). The related macro trace and top-level command :trace do not accept function objects as
arguments.

The various keyword arguments (condition,
break-before, break-after,
inside, not-inside,
print-before, print-after)
are a subset of those accepted by the :trace top-level command and have the same
effect. See that page for details.

The :trace top-level command also
accepts the keyword arguments break-all and
print-all, which are not accepted by ftrace. To achieve the effect of
specifying either of those, specify both the associated
before and after arguments
as true. Thus, to get the effect of :print-all t
passed to :trace, specify
:print-before t :print-after t to ftrace; similarly specify
:break-before t :break-after t in place of
:break-all t.